JP7113237B2 - Mounting mechanism and electric motor using the same - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a mounting mechanism for mounting a rotating body on a rotating shaft and an electric motor using the mounting mechanism to mount an encoder. The motor has an encoder attached using an attachment mechanism.

Conventionally, some electric motors are equipped with rotary encoders. The rotary encoder includes a boss, a light emitting diode as a light source, a substrate on which a position detection pattern is formed, and a rotating plate attached to the boss and formed with a translucent window through which light from the light emitting diode passes. .

The boss is attached by tightening with a screw or the like to the rotating shaft of the electric motor.

A rotating plate is located between the light emitting diode and the substrate. The rotating plate rotates with the rotating shaft.

When the rotating plate rotates, the light emitted from the light emitting diode passes through the translucent window formed in the rotating plate and reaches the position detection pattern (see Patent Documents 1 and 2, for example).

The boss is fixed to the rotary shaft by tightening it with a screw or the like from its outer peripheral side surface. At this time, the tightening of the screw may cause a deviation between the rotation center of the boss and the rotation center of the rotating shaft. Due to the generated deviation, in the rotary encoder, a runout occurs in the rotary plate with respect to the rotation center of the rotary encoder, that is, the rotation center of the rotary shaft. When the rotary plate runs out, the detection accuracy of the position detection pattern provided on the rotary plate is lowered, resulting in a problem that desired control by the rotary encoder cannot be performed. In addition, in the following description, the center of rotation is also referred to as the axis.

JP-A-08-168210 JP 2008-228397 A

An object of the present disclosure is to suppress core runout of a rotating body when attaching a device having the rotating body such as a rotating plate to a shaft body such as a rotating shaft.

The present disclosure is directed to an attachment mechanism for attaching a rotating body to a rotating shaft and an electric motor to which a rotary encoder is attached using the attachment mechanism, and takes the following solutions.

That is, one aspect of the present disclosure is an attachment mechanism that attaches a rotating body to a rotating shaft. The attachment mechanism includes a first nut, a second nut and a ring body.

The first nut includes a cylindrical portion and a flange portion. A rotating shaft passes through the cylindrical portion. The cylindrical portion extends along the axis of the rotating shaft and has a first outer peripheral surface including a first screw thread. The flange portion has a first inner peripheral surface that protrudes in a direction that intersects the axis and is opposite to the side where the rotation shaft is located, and that includes a first thread groove.

The second nut is passed through by the rotating shaft. The second nut includes a second thread and an eyelet. The second thread groove is formed in a portion of the second inner peripheral surface facing the rotating shaft and is screwed with the first thread. The small hole is formed in a portion of the second inner peripheral surface other than the second thread groove and is fitted with the rotating shaft.

The ring body is penetrated by the rotating shaft and positioned between the third inner peripheral surface of the cylindrical portion and the rotating shaft. When the first nut and the second nut are screwed together in the direction of approaching each other, the ring body absorbs the force acting along the axial center from each of the first nut and the second nut. It has a first slanted surface that converts a force acting in a direction transverse to the center.

Another aspect of the present disclosure includes a rotor having a rotor core attached to a rotating shaft, a bearing that rotatably supports the rotating shaft, and a stator that faces the rotor, and is described in the present disclosure. is an electric motor in which an encoder is attached to a rotary shaft using the attachment mechanism of

Advantageous Effects of Invention According to the present disclosure, when a device having a rotating body such as a rotating plate is attached to a rotating shaft, it is possible to suppress core runout of the rotating body.

FIG. 1 is a cross-sectional view showing an outline of an electric motor using an attachment mechanism according to Embodiment 1 of the present disclosure. FIG. 2 is an exploded perspective view showing an attachment mechanism according to Embodiment 1 of the present disclosure and an encoder attached by the attachment mechanism. FIG. 3 is a cross-sectional view showing an attachment mechanism according to Embodiment 1 of the present disclosure and an encoder attached to the attachment mechanism. FIG. 4 is a schematic cross-sectional view showing the action of the mounting mechanism according to Embodiment 1 of the present disclosure on the rotating shaft. FIG. 5 is a perspective view of one member that configures the attachment mechanism according to Embodiment 1 of the present disclosure. FIG. 6 is a front view of one member that configures the mounting mechanism according to Embodiment 1 of the present disclosure. 7 is a front view of another member that configures the attachment mechanism according to Embodiment 1 of the present disclosure. FIG. FIG. 8 is a perspective view of another member that configures the attachment mechanism according to Embodiment 1 of the present disclosure. FIG. 9 is a schematic cross-sectional view showing the action of the mounting mechanism according to Embodiment 2 of the present disclosure on the rotating shaft. FIG. 10 is a perspective view of one member that configures an attachment mechanism according to Embodiment 2 of the present disclosure. FIG. 11 is a front view of one member that configures an attachment mechanism according to Embodiment 2 of the present disclosure. FIG. 12 is a front view of another member that configures the mounting mechanism according to Embodiment 2 of the present disclosure. FIG. 13 is a perspective view of another member that configures the attachment mechanism according to Embodiment 2 of the present disclosure. FIG. 14 is a schematic cross-sectional view showing the action of the attachment mechanism according to Embodiment 3 of the present disclosure on the rotating shaft. 15 is a perspective view of one member that configures an attachment mechanism according to Embodiment 3 of the present disclosure. FIG. 16 is a front view of one member that configures an attachment mechanism according to Embodiment 3 of the present disclosure. FIG. 17 is a front view of another member that configures the attachment mechanism according to Embodiment 3 of the present disclosure. FIG. 18 is a perspective view of another member that configures the attachment mechanism according to Embodiment 3 of the present disclosure. FIG. FIG. 19 is a schematic cross-sectional view showing action on a rotating shaft in an attachment mechanism according to Embodiment 4 of the present disclosure. FIG. 20 is a perspective view of one member that configures an attachment mechanism according to Embodiment 4 of the present disclosure. FIG. 21 is a front view of one member that configures an attachment mechanism according to Embodiment 4 of the present disclosure. FIG. 22 is a front view of another member that configures the attachment mechanism according to Embodiment 4 of the present disclosure. FIG. 23 is a perspective view of another member that configures the attachment mechanism according to Embodiment 4 of the present disclosure. 24 is a front view of one member that configures an attachment mechanism according to Embodiment 5 of the present disclosure. FIG. 25 is a front view of another member that configures the attachment mechanism according to Embodiment 5 of the present disclosure. FIG.

(Circumstances leading to this disclosure)
2. Description of the Related Art Conventionally, an electric motor capable of position control, speed control, etc. is used as a power source for transporting various parts or products or for moving an XY stage. Such an electric motor is generally equipped with an optical or magnetic rotary encoder (hereinafter simply referred to as an encoder) as means for detecting the rotational speed and rotational angle of the rotary shaft.

A position detection pattern is formed on the rotating plate. An encoder is attached to the rotating shaft. Therefore, in order to improve the position detection accuracy of the encoder, it is important to accurately position the rotation center of the rotating plate with respect to the rotation center of the rotating shaft.

The rotating plate is attached to and held by a boss, which is a reinforcing part that reinforces the cylindrical shaft. A boss to which the rotating plate is attached has an axial hole. The shaft hole is inserted into the rotary shaft to which the encoder is attached. The boss is fixed to the rotating shaft. Specifically, the boss is fixed to the rotating shaft by, for example, tightening a screw from its outer peripheral side surface.

Regarding the encoder configured in this way, first, the mounting accuracy of the rotary plate to the boss depends on the positioning accuracy between the rotation center of the rotary shaft and the rotation center of the boss. Therefore, if there is a gap between the shaft hole of the boss and the rotating shaft of the electric motor, a deviation occurs between the center of rotation of the rotating shaft and the center of rotation of the boss. Therefore, it becomes difficult to improve the mounting accuracy of the rotary plate to the boss. Therefore, it becomes difficult to suppress the run-out of the rotating plate that rotates together with the rotating shaft.

The attachment accuracy of the boss to the rotating shaft also depends on the positioning accuracy between the rotation center of the rotation shaft and the rotation center of the boss. Therefore, if there is a gap between the shaft hole of the boss and the rotating shaft, tightening of the screw causes a deviation between the center of rotation of the boss and the center of rotation of the rotating shaft. For this reason, it becomes difficult to improve the attachment accuracy of the boss to the rotating shaft. Therefore, even in this case, it becomes difficult to suppress the run-out of the rotating plate with respect to the rotating shaft.

The present disclosure is made in view of the above problems. Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of known matters or redundant descriptions of substantially the same configurations may be omitted. This is to avoid unnecessary verbosity in the following description, thereby facilitating the understanding of those skilled in the art.

It should be noted that the accompanying drawings and the following description are provided to allow those skilled in the art to fully understand the present disclosure and are not intended to limit the claimed subject matter.

(Embodiment 1)
Embodiments of the present disclosure will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing an outline of an electric motor 200 using an attachment mechanism according to Embodiment 1 of the present disclosure.

(Overview of electric motor)
As an embodiment of the present disclosure, a form in which an encoder is attached to an electric motor using an attachment mechanism will be exemplified and described. It should be noted that the attachment mechanism in the present disclosure can be used for other than electric motors as long as the rotating body can be attached to the rotating shaft.

As shown in FIG. 1 , electric motor 200 according to the embodiment of the present disclosure includes rotor 210 , bearing 220 , and stator 230 .

A rotor core 212 is attached to the rotating shaft 110 in the rotor 210 . In the present embodiment, rotor core 212 is formed by laminating thin steel plates in the axial center C direction of rotating shaft 110 . A plurality of magnet holes 214 are formed in the laminated rotor core 212 along the axis C of the rotating shaft 110 . A permanent magnet 216 is inserted into each of the magnet holes 214 .

Bearing 220 rotatably supports rotating shaft 110 . In the present embodiment, a pair of bearings 220 are positioned so as to sandwich rotor core 212 . A pair of bearings 220 are each held in a case 222 forming an outer shell of electric motor 200 .

Stator 230 is positioned opposite rotor 210 . In this embodiment, stator 230 includes stator core 232 and windings 234 . Stator core 232 is formed by laminating thin steel plates along axis C of rotating shaft 110 . The laminated stator core 232 has a plurality of teeth protruding toward the axis C. As shown in FIG. Slots are formed between adjacent teeth among the plurality of teeth. Windings 234 are wound around stator core 232 using slots. Winding 234 is wound around stator core 232 via insulator 236 which is an insulator.

The encoder 100 is attached to the rotary shaft 110 using the attachment mechanism 40 .

The mounting mechanism 40 includes a boss fixing nut 10 that is a first nut, a lock nut 20 that is a second nut, and a tapered ring 30 that is a ring body.

Encoder 100 includes an LED (Light Emitting Diode) element 151 that is a light emitting element, a phototransistor (Phototransistor) 152 that is a light receiving element, and a boss body 120 that fixes rotating plate 130 to rotating shaft 110 . The rotating plate 130 is formed with a translucent window through which the light emitted by the LED element 151 passes.

Details of the mounting mechanism 40 and the encoder 100 will be described later.

In this configuration, windings 234 are supplied with drive current from the outside of electric motor 200 . A winding 234 supplied with drive current generates a predetermined magnetic flux through the stator core 232 . Permanent magnets 216 embedded in rotor core 212 are affected by magnetic flux generated in stator core 232 . Rotor 210 rotates around rotating shaft 110 under the influence of the magnetic flux received by permanent magnet 216 .

Rotating plate 130 attached to rotating shaft 110 using attachment mechanism 40 rotates together with rotor 210 .

The LED element 151 forming the encoder 100 emits light. The phototransistor 152 receives light emitted by the LED element 151 . Since the rotating plate 130 rotates, the light emitted by the LED element 151 is received by the phototransistor 152 only when the translucent window formed in the rotating plate 130 passes between the LED element 151 and the phototransistor 152. . At other times, the light emitted by the LED element 151 is blocked by the rotating plate 130 , so the phototransistor 152 cannot receive the light emitted by the LED element 151 .

The light emitted by the LED element 151 is received by the phototransistor 152, so that the encoder 100 can detect the state in which the rotor 210 is rotating. In response to the detected rotational state of rotor 210 , the control unit of electric motor 200 controls the drive current that flows through winding 234 .

As will be described later, encoder 100 in the present embodiment can be attached so that axis J of boss body 120 is positioned on axis C of rotating shaft 110 . Therefore, it is possible to suppress the occurrence of deviation between the rotation center of rotating shaft 110 and the rotation center of boss body 120 . Therefore, the encoder 100 can detect the rotation state of the rotor 210 with high accuracy.

In the above description, the motor 200 is exemplified by a brushless motor having a magnet-embedded rotor. Motors in accordance with the present disclosure may also be used with other forms of brushless motors, commutator motors, induction motors, or the like. Also, the electric motor according to the present disclosure can be used as an inner rotor type motor or an outer rotor type motor.

(Encoder configuration)
FIG. 2 is an exploded perspective view showing the mounting mechanism 40 and the encoder 100 mounted by the mounting mechanism 40 according to the first embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing attachment mechanism 40 and encoder 100 attached to attachment mechanism 40 according to the first embodiment of the present disclosure.

As shown in FIGS. 2 and 3, the rotating body according to the present embodiment is encoder 100 including boss body 120 and rotating plate 130 .

The rotation shaft 110 passes through the boss body 120 . Boss body 120 extends along axis C of rotating shaft 110 . The boss body 120 has a second outer peripheral surface 124 including a second thread 122 that is screwed into the first thread groove 18 included in the flange portion 10B.

The rotating plate 130 is attached so as to intersect the axis C. As shown in FIG. Specifically, the rotating plate 130 is formed so as to extend in a plane direction having the axis C as a normal line.

A more detailed description will be given with reference to the drawings.

As shown in FIGS. 2 and 3, for example, encoder 100 is attached to the end of rotating shaft 110 by attachment mechanism 40 according to the present embodiment. Here, the rotating shaft 110 is the shaft of the electric motor. It should be noted that the mounting mechanism 40 according to the present disclosure can be used not only for the shaft of the electric motor, but also for shafts having similar functions.

The encoder 100 has a boss body 120 that is a rotating body that fits on the rotating shaft 110 and is held by the mounting mechanism 40 . A rotary plate 130 for detecting a rotational position or rotational speed is held on the protrusion 120 a of the boss body 120 so as to be perpendicular to the axis J of the boss body 120 . Rotating plate 130 is attached to boss body 120 by screwing, fitting, adhesive, or the like. The rotating plate 130 is formed with a translucent window 131 which is a transmissive pattern for position detection and selectively transmits light. The translucent window 131 can be made of, for example, a transparent glass material or resin material.

Also, as shown in FIG. 3, the encoder 100 is an optical detector in which, for example, an LED element 151 as a light emitting element and a phototransistor 152 as a light receiving element are arranged in a housing 100a. The housing 100 a is made of, for example, a metal plate and is attached so as to surround the encoder 100 .

The light emitting element may be, for example, an LED element 151 . Other elements can be used as the light-emitting elements as long as they have similar functions. The light receiving element may be, for example, a phototransistor 152 . Other elements can be used as the light receiving elements as long as they have similar functions. The LED element 151 and the phototransistor 152 are arranged inside the housing 100a at positions facing each other with the rotating plate 130 interposed therebetween. Therefore, light emitted from the LED element 151 and transmitted through the rotary plate 130 is received by the phototransistor 152 and is electrically detected. Furthermore, a circuit board mounted with a control circuit for controlling each of the LED element 151 and the phototransistor 152 may be arranged inside the housing 100a.

Further, the boss body 120 held by the rotary shaft 110 is rotatably supported by the housing 100a via a bearing mechanism 140 and about the axis J as the rotation center. The housing 100a may be held by an external member or the like (not shown) via a leaf spring or the like, for example.

(Configuration of mounting mechanism)
FIG. 4 is a schematic cross-sectional view showing the action on rotating shaft 110 in attachment mechanism 40 according to Embodiment 1 of the present disclosure. FIG. 5 is a perspective view of one member that configures the attachment mechanism 40 according to Embodiment 1 of the present disclosure. FIG. 6 is a front view of one member that configures the attachment mechanism 40 according to Embodiment 1 of the present disclosure. FIG. 7 is a front view of another member that configures the attachment mechanism 40 according to Embodiment 1 of the present disclosure. FIG. 8 is a perspective view of another member that configures the mounting mechanism 40 according to Embodiment 1 of the present disclosure.

As shown in FIGS. 2 to 4, the mounting mechanism 40 according to the present embodiment is composed of three annular members penetrating the rotary shaft 110, respectively.

That is, attachment mechanism 40 according to the present embodiment attaches boss body 120 , which is a rotating body, to rotating shaft 110 .

The mounting mechanism 40 includes a boss fixing nut 10 that is a first nut, a lock nut 20 that is a second nut, and a tapered ring 30 that is a ring body.

A rotating shaft 110 passes through the boss fixing nut 10 . The boss fixing nut 10 includes a cylindrical portion 10A and a flange portion 10B.

Cylindrical portion 10A extends along axis C of rotating shaft 110 and has first outer peripheral surface 12 including first thread 14 . The flange portion 10B is convex in a direction that intersects the axis C and opposite to the side on which the rotating shaft 110 is located, and has a first inner peripheral surface 16 including a first thread groove 18. have. A first inner peripheral surface 16 of the flange portion 10B is positioned to face the rotating shaft 110 .

A rotating shaft 110 passes through the lock nut 20 . Locknut 20 includes a second threaded groove 22 and an eyelet 24 .

The second thread groove 22 is formed in a portion of the second inner peripheral surface 26 facing the rotary shaft 110, and is connected to the first thread 14 of the boss fixing nut 10, which is the first nut. match. The small hole portion 24 is formed in a portion of the second inner peripheral surface 26 other than the second thread groove 22 and is fitted with the rotating shaft 110 .

A rotary shaft 110 passes through the tapered ring 30 which is a ring body. The tapered ring 30 is positioned between the third inner peripheral surface 17 of the cylindrical portion 10A and the rotating shaft 110. As shown in FIG. When the boss fixing nut 10, which is the first nut, and the lock nut 20, which is the second nut, are screwed together in the direction (D1, D2 in FIG. Forces F01 and F02 acting in a direction along the axis C applied from a certain boss fixing nut 10 and a lock nut 20 which is a second nut are combined into forces F1 and F2 acting in a direction intersecting the axis C. It has an inclined surface 32 that transforms into

In particular, the form with remarkable effects is as follows.

The ring bodies used in the attachment mechanism 40 are a pair of tapered rings 30 each having inclined surfaces 32a, 32b facing and abutting each other. The tapered ring 30 is an example of a ring body such as a span ring, and has an outer ring 30a and an inner ring 30b.

In the present embodiment, the inclined surface 32 is composed of a first inclined surface and a second inclined surface facing and abutting the first inclined surface. In the following description, the inclined surface 32a of the outer ring 30a functions as a first inclined surface. On the other hand, the inclined surface 32b of the inner ring 30b functions as a second inclined surface.

A more detailed description will be given with reference to the drawings.

As shown in FIGS. 3 and 4, the boss fixing nut 10 includes a flange portion 10B and a cylindrical portion 10A. A first thread groove 18 is formed in the first inner peripheral surface 16 of the flange portion 10B facing the boss body 120 . The cylindrical portion 10A has a first outer peripheral surface 12 on the side opposite to the side where the boss body 120 is located. A first thread 14 is formed on the first outer peripheral surface 12 .

A second screw thread 122 is formed at an end portion 120b of the boss body 120 located on the opposite side of the protrusion 120a formed on the boss body 120 in the direction of the axis J. As shown in FIG. The second thread 122 is screwed into the first thread groove 18 formed in the boss fixing nut 10 .

The lock nut 20 fixes the boss fixing nut 10 to the boss body 120 . A part of the second inner peripheral surface 26 of the lock nut 20 is formed with a second thread groove 22 that engages with the first thread 14 formed on the boss fixing nut 10 . The lock nut 20 has a small hole portion 24 in at least a part of the remaining portion of the second inner peripheral surface 26 of the lock nut 20 to fit the rotating shaft 110 .

Here, the cylindrical portion 10A of the boss fixing nut 10 is formed such that a gap portion 10C is formed between the rotating shaft 110 and the cylindrical portion 10A. A pair of tapered rings 30 are inserted into the gap 10C. A pair of tapered rings 30 has an outer ring 30a and an inner ring 30b, each having inclined surfaces 32a, 32b facing and abutting each other. In the pair of tapered rings 30, when the lock nut 20 is screwed in the direction D2 of the boss fixing nut 10, the inclined surface 32a of the outer ring 30a slides outside the inclined surface 32b of the inner ring 30b. In other words, in the pair of tapered rings 30, the inclined surface 32b of the inner ring 30b is recessed inside the inclined surface 32a of the outer ring 30a. As a result, the thickness of the tapered ring 30 increases in the direction intersecting the axis C, so that the outer diameter of the tapered ring 30 increases. Therefore, as shown in FIG. 4, the tapered ring 30 having an enlarged outer diameter has an outward action acting on the boss fixing nut 10 and the lock nut 20 in a direction intersecting with the axis C and directed outward. A force F1 is generated. Therefore, the boss body 120 generates a force F2 as its reaction. As a result, in the direction crossing the axis C, the boss body 120 is strongly pressed toward the axis C in all directions from around the boss fixing nut 10 and the lock nut 20 . That is, the axis J (rotation center) of the boss fixing nut 10 , the lock nut 20 and the taper ring 30 all coincide with the axis C (rotation center) of the boss body 120 . Therefore, it is possible to suppress core runout of the boss body 120, which is a body of rotation, and by extension, the rotor plate 130. As shown in FIG.

It is preferable that the coefficient of friction of the inclined surfaces 32a and 32b, which are contact surfaces (sliding surfaces) of the outer ring 30a and the inner ring 30b forming the tapered ring 30, be large.

As shown in FIG. 4 , it is preferable that the end surface 34 of the tapered ring 30 on the side of the boss fixing nut 10 is in contact with the end surface 120 c of the boss body 120 on the side of the boss fixing nut 10 . Alternatively, the end surface 34 of the taper ring 30 on the side of the boss fixing nut 10 may be in contact with the inner surface 10d of the flange portion 10B of the boss fixing nut 10 .

Furthermore, it is preferable that the end surface 34a of the tapered ring 30 located on the side of the small hole portion 24 of the lock nut 20 is in contact with the inner surface 20a of the small hole portion 24 .

With this configuration, the action force F1 and the reaction force F2 can be reliably generated.

With the following configuration, it is possible to obtain even more remarkable effects.

As shown in FIG. 5, of the pair of tapered rings 30 used in the mounting mechanism 40, the inner ring 30b, which is the tapered ring located on the rotating shaft 110 side, is arranged so that its extension intersects the axis C. It is sufficient to have slits 36 formed therein. In other words, inner ring 30b has slit 36 . An extension line of the slit 36 intersects the axis C. As shown in FIG. Here, the extension line of the slit 36 refers to a line extending in the direction in which the slit 36, which is a narrow gap, is cut.

Alternatively, as shown in FIGS. 6 and 7, of the pair of tapered rings 30 used in the mounting mechanism 40, the inner ring 30b, which is the tapered ring located on the rotating shaft 110 side, has an extension line extending from the axis C. It is sufficient to have a plurality of slits 36 formed so as to intersect with the . In other words, the inner ring 30b has multiple slits 36 . Extension lines of the plurality of slits 36 intersect the axis C, respectively. On a plane orthogonal to the axis C, the plurality of slits 36 may be positioned at intervals in the circumferential direction centered on the axis C, respectively.

A slit 36 is formed along the inclined surface 32 . When the center line of the slit 36 is extended, the extension line should intersect the axis C.

In other words, on a plane orthogonal to the axis C, the plurality of slits 36 may be positioned radially around the axis C and circumferentially at appropriate angles.

As a particularly preferable example, as shown in FIG. 6, each slit 36 may be positioned at every θ1=120°. Alternatively, as shown in FIG. 7, each slit 36 may be positioned at every θ2=90°.

In the specific example shown in FIGS. 6 and 7, the slits 36 are equally spaced. Equal intervals or appropriate angles mean that the holding forces applied to the rotating shaft 110 by the respective inclined surfaces 32b divided by the respective slits 36 are equal, and are not meant to be mathematical equality. Typically, variations due to manufacturing tolerances are within the range of equidistant intervals or appropriate angles as referred to in this embodiment.

With this configuration, in the direction intersecting the axis C, the inner ring 30b presses the boss body 120 more strongly toward the axis C in all directions from the periphery of the boss fixing nut 10 and the lock nut 20. can be done. That is, the inner ring 30b can adjust the strength with which the boss body 120 is tightened within a range that can be adjusted by the width dimension of the slit 36 . Therefore, the accuracy with which the axis J (rotation center) of the boss fixing nut 10, the lock nut 20, and the taper ring 30 coincide with the axis C (rotation center) of the boss body 120 is improved. Therefore, it is possible to further suppress core runout of the boss body 120, which is a body of rotation, and by extension, the rotor plate 130 as well.

Especially when the three slits 36 shown in FIG. 6 or the four slits 36 shown in FIG. The number of man-hours for forming the slits 36 in the inclined surface 32b can also be achieved within a moderate number of man-hours.

As shown in FIG. 8, for the slit 36a used in the mounting mechanism 40, the slit width W2 on the opening 36c side should be wider than the slit width W1 on the tip 36b side. In other words, the slit 36a of the inner ring 30b of the tapered ring located on the rotating shaft 110 side has a slit width W2 on the side of the opening 36c of the tapered ring that is wider than the slit width W1 on the tip 36b side of the tapered ring. there is

With this configuration, even if a gap is generated between the inner peripheral surface of the inner ring 30b and the outer peripheral surface of the rotating shaft 110 due to some factor, the difference between the slit width W2 and the slit width W1 is enough to fill the gap. Absorb. In other words, due to the presence of the difference between the slit width W2 and the slit width W1, the inner ring 30b and the rotating shaft 110 can always secure an appropriate holding force.

As described above, the mounting mechanism 40 of the present embodiment is a mounting mechanism 40 for mounting a rotating body corresponding to the boss body 120 to the rotating shaft 110, and includes the first nut 10, the second nut 20, a ring body 30;

The first nut 10 includes a cylindrical portion 10A and a flange portion 10B. The rotating shaft 110 passes through the cylindrical portion 10A. Cylindrical portion 10A extends along axis C of rotating shaft 110 and has first outer peripheral surface 12 including first thread 14 . The flange portion 10B is convex in a direction that intersects the axis C and opposite to the side on which the rotating shaft 110 is located, and has a first inner peripheral surface 16 including a first thread groove 18. have.

The rotating shaft 110 passes through the second nut 20 . The second nut 20 includes a second threaded groove 22 and an eyelet 24 . The second thread groove 22 is formed in a portion of the second inner peripheral surface 26 facing the rotating shaft 110 and is screwed with the first thread 14 . The small hole portion 24 is formed in a portion of the second inner peripheral surface 26 other than the second thread groove 22 and is fitted with the rotating shaft 110 .

The ring body 30 is penetrated by the rotating shaft 110 and is positioned between the rotating shaft 110 and the third inner peripheral surface 17 of the cylindrical portion 10A. When the first nut 10 and the second nut 20 are screwed together in the direction of approaching each other, the ring body 30 is pushed in the direction along the axis C by the first nut 10 and the second nut 20 respectively. has a first slanted surface corresponding to the slanted surface 32a that converts the force acting on the axis C into a force acting in a direction intersecting the axis C. As shown in FIG.

As a result, the core run-out of the rotating body corresponding to the boss body 120 can be suppressed.

Moreover, the ring body 30 may be a pair of tapered rings 30 further having a second inclined surface corresponding to the inclined surface 32b that faces and contacts the first inclined surface corresponding to the inclined surface 32a.

Further, of the pair of tapered rings 30, the tapered ring corresponding to the inner ring 30b located on the rotating shaft 110 side has a slit 36. As shown in FIG. The extension line of the slit 36 should just intersect the axis C. As shown in FIG.

Further, of the pair of tapered rings 30, the tapered ring corresponding to the inner ring 30b located on the rotating shaft 110 side has a plurality of slits 36. As shown in FIG. Extension lines of the plurality of slits 36 intersect the axis C, respectively. On a plane orthogonal to the axis C, the plurality of slits 36 may be positioned at intervals in the circumferential direction around the axis C. As shown in FIG.

In addition, the slit 36a of the tapered ring corresponding to the inner ring 30b located on the rotating shaft 110 side is wider than the slit width W1 on the tip 36b side of the tapered ring corresponding to the inner ring 30b. The slit width W2 on the side of the opening 36c should be wider.

Moreover, in the mounting mechanism 40 , the rotating body may be the encoder 100 including the boss body 120 and the rotating plate 130 . The rotation shaft 110 passes through the boss body 120 . The boss body 120 extends along the axis C of the rotating shaft 110 and has a second outer peripheral surface 124 including a second thread 122 that is screwed into the first thread groove 18 included in the flange portion 10B. do it. The rotating plate 130 may be attached so as to intersect the axis C.

Further, the electric motor 200 of the present embodiment includes a rotor 210 having a rotor core 212 attached to a rotating shaft 110, a bearing 220 rotatably supporting the rotating shaft 110, and a stator facing the rotor 210. 230 and. The encoder 100 is attached to the rotary shaft 110 using the attachment mechanism 40 described above.

(Embodiment 2)
A configuration of the mounting mechanism 440 according to the second embodiment will be described.

FIG. 9 is a schematic cross-sectional view showing the action on rotating shaft 110 in attachment mechanism 440 according to the second embodiment of the present disclosure. FIG. 10 is a perspective view of one member that configures attachment mechanism 440 according to Embodiment 2 of the present disclosure. FIG. 11 is a front view of one member that configures attachment mechanism 440 according to Embodiment 2 of the present disclosure. FIG. 12 is a front view of another member that configures attachment mechanism 440 according to Embodiment 2 of the present disclosure. FIG. 13 is a perspective view of another member that configures attachment mechanism 440 according to Embodiment 2 of the present disclosure.

In describing the attachment mechanism 440, the same reference numerals are assigned to the same components as those of the first embodiment described above, and the description thereof is incorporated.

As shown in FIG. 9, a boss body 460, which is a rotating body on which the mounting mechanism 440 is used, has a tapered shape extending between the third inner peripheral surface 17 and the rotating shaft 110 in the direction along the axis C. It has a part 462 . The tapered portion 462 includes an inclined surface 432b facing the inclined surface 432a of the tapered ring 430, which is a ring body.

In the following description, the inclined surface 432a of the tapered ring 430 functions as a first inclined surface. On the other hand, the inclined surface 432b of the tapered portion 462 functions as a second inclined surface.

A more detailed description will be given with reference to the drawings.

As shown in FIG. 9, the boss fixing nut 10 includes a flange portion 10B and a cylindrical portion 10A. A first thread groove 18 is formed in the first inner peripheral surface 16 of the flange portion 10B facing the boss body 460 . The cylindrical portion 10A has a first outer peripheral surface 12 on the side opposite to the side where the boss body 460 is located. A first thread 14 is formed on the first outer peripheral surface 12 .

A second screw thread 122 is formed at an end portion 460b of the boss body 460 located on the opposite side of the protrusion formed on the boss body 460 in the direction of the axis J. As shown in FIG. The second thread 122 is screwed into the first thread groove 18 formed in the boss fixing nut 10 .

The lock nut 20 fixes the boss fixing nut 10 to the boss body 460 . A part of the second inner peripheral surface 26 of the lock nut 20 is formed with a second thread groove 22 that engages with the first thread 14 formed on the boss fixing nut 10 . The lock nut 20 has a small hole portion 24 in at least a part of the remaining portion of the second inner peripheral surface 26 of the lock nut 20 to fit the rotating shaft 110 .

Here, the cylindrical portion 10A of the boss fixing nut 10 is formed so as to create a gap portion 410C between the tapered portion 462 and the cylindrical portion 10A. A tapered ring 430 is inserted into the gap 410C. The tapered ring 430 has an inclined surface 432a that faces and abuts against an inclined surface 432b that the tapered portion 462 has. When the lock nut 20 is screwed into the boss fixing nut 10 in the direction D2, the tapered surface 432a of the tapered ring 430 slides outside the tapered surface 432b of the tapered portion 462. As shown in FIG. In other words, in the tapered portion 462 , the inclined surface 432 b of the tapered portion 462 slips inside the inclined surface 432 a of the tapering 430 . As a result, the taper ring 430 moves away from the axis C of the rotating shaft 110 in the direction intersecting with the axis C, so that the outer diameter of the taper ring 430 increases. Therefore, as shown in FIG. 9, the tapered ring 430 having an enlarged outer diameter acts outwardly in a direction intersecting the axis C with respect to the boss fixing nut 10 and the lock nut 20. A certain force F1 is generated. Therefore, the boss body 460 generates a force F2 as its reaction. As a result, in the direction crossing the axis C, the boss body 460 is strongly pressed toward the axis C in all directions from around the boss fixing nut 10 and the lock nut 20 . That is, the axis J (rotation center) of the boss fixing nut 10 , the lock nut 20 and the taper ring 430 all coincide with the axis C (rotation center) of the boss body 460 . Therefore, it is possible to suppress core runout of the boss body 460, which is a body of rotation, and by extension, the rotor plate 130 as well.

The contact surface (sliding surface) where the inclined surface 432a of the tapered ring 430 and the inclined surface 432b of the tapered portion 462 contact each other preferably has a large coefficient of friction.

With the following configuration, it is possible to obtain even more remarkable effects.

As shown in FIG. 10, the tapered portion 462 of the boss body 460 may have a slit 436 formed so that the extension line intersects the axis C. As shown in FIG. In other words, tapered portion 462 has slit 436 . Here, the extension line of the slit 436 refers to a line extending in the direction in which the slit 436, which is a narrow gap, is cut.

Alternatively, as shown in FIGS. 11 and 12, the tapered portion 462 of the boss body 460 may have a plurality of slits 436 formed so that the extension lines thereof intersect the axis C. As shown in FIGS. In other words, tapered portion 462 has a plurality of slits 436 . Extension lines of the plurality of slits 436 intersect the axis C, respectively. On a plane orthogonal to the axis C, the plurality of slits 436 may be positioned at intervals in the circumferential direction around the axis C, respectively.

A slit 436 is formed along the inclined surface 432b. When the center line of the slit 436 is extended, the extended line should intersect the axis C.

In other words, on a plane orthogonal to the axis C, the plurality of slits 436 may be positioned radially around the axis C and on the circumference at appropriate angles.

As a particularly preferable example, as shown in FIG. 11, each slit 436 may be positioned at every θ1=120°. Alternatively, as shown in FIG. 12, each slit 436 may be positioned every θ2=90°.

In the specific example shown in FIGS. 11 and 12, the slits 436 are evenly spaced. Equal spacing or an appropriate angle means that the holding forces applied to the rotating shaft 110 by the respective inclined surfaces 432b divided by the respective slits 436 are equal, and does not mean mathematical equality. Typically, variations due to manufacturing tolerances are within the range of equidistant intervals or appropriate angles as referred to in this embodiment.

With this configuration, in the direction intersecting the axis C, the tapered portion 462 presses the boss body 460 more strongly toward the axis C in all directions from the periphery of the boss fixing nut 10 and the lock nut 20. can be done. In other words, the taper portion 462 can adjust the strength with which the boss body 460 is tightened within a range that can be adjusted by the width dimension of the slit 436 . Therefore, the accuracy with which the axis J (rotational center) of the boss fixing nut 10, the lock nut 20, and the tapered ring 430 are aligned with the axis C (rotational center) of the boss body 460 is improved. As a result, the boss body 460, which is a body of rotation, and by extension the wobbling of the rotor plate 130 can be further suppressed.

Especially when three slits 436 shown in FIG. 11 or four slits 436 shown in FIG. The number of man-hours for forming the slits 436 in the inclined surface 432b can also be realized within a moderate number of man-hours.

As shown in FIG. 13, the slit 436a should have a slit width W2 on the opening 436c side that is wider than the slit width W1 on the tip 436b side. In other words, the slit 436a of the tapered portion 462 has a slit width W2 on the side of the opening 36c of the tapered portion 462 that is wider than the slit width W1 on the tip 436b side of the tapered portion 462 .

With this configuration, even if a gap is generated between the inner peripheral surface of the tapered portion 462 and the outer peripheral surface of the rotating shaft 110 due to some factor, the difference between the slit width W2 and the slit width W1 is enough to fill the gap. Absorb. That is, due to the presence of the difference between the slit width W2 and the slit width W1, the tapered portion 462 and the rotating shaft 110 can always secure an appropriate holding force.

As is clear from the above description, in the second embodiment described above, boss body 460 has tapered portion 462 extending between third inner peripheral surface 17 of boss fixing nut 10 and the outer peripheral surface of rotating shaft 110 . have The tapered portion 462 has a function corresponding to that of the inner ring 30b described in the first embodiment. In this configuration, the tapered ring 430 has a function corresponding to that of the outer ring 30a described in the first embodiment. That is, in the second embodiment, the taper ring 430 can be made up of one member as compared with the first embodiment. Therefore, in the second embodiment, as compared with the mounting mechanism 40 shown in the first embodiment, assembling workability is improved.

As described above, the rotating body corresponding to boss body 460 of the present embodiment has tapered portion 462 extending between third inner peripheral surface 17 and rotating shaft 110 in the direction along axis C. have. The tapered portion 462 includes a first inclined surface corresponding to the inclined surface 432a and a second inclined surface corresponding to the inclined surface 432b opposite to the inclined surface 432a.

As a result, the core run-out of the rotating body corresponding to the boss body 460 can be suppressed.

Also, the tapered portion 462 has a slit 436 . An extension line of the slit 436 may intersect the axis C.

Also, the tapered portion 462 has a plurality of slits 436 . Extension lines of the plurality of slits 436 intersect the axis C, respectively. On a plane orthogonal to the axis C, the plurality of slits 436 may be positioned along the circumference of the axis C at intervals.

Further, the slit 436a of the tapered portion 462 may have a slit width W2 on the side of the opening 436c of the tapered portion 462 that is wider than the slit width W1 on the tip 436b side of the tapered portion 462 .

(Embodiment 3)
A configuration of the attachment mechanism 540 according to the third embodiment will be described.

FIG. 14 is a schematic cross-sectional view showing the action of attachment mechanism 540 according to the third embodiment of the present disclosure on rotating shaft 110. As shown in FIG. FIG. 15 is a perspective view of one member that configures the attachment mechanism 540 according to Embodiment 3 of the present disclosure. FIG. 16 is a front view of one member that configures attachment mechanism 540 according to Embodiment 3 of the present disclosure. FIG. 17 is a front view of another member that configures attachment mechanism 540 according to Embodiment 3 of the present disclosure. FIG. 18 is a perspective view of another member that configures attachment mechanism 540 according to Embodiment 3 of the present disclosure.

In describing the mounting mechanism 540, the same reference numerals are assigned to the same components as those of the first and second embodiments described above, and the description thereof is incorporated.

As shown in FIG. 14, the third inner peripheral surface 517 of the boss fixing nut 510, which is the first nut used in the mounting mechanism 540, has an inclination opposite to the inclined surface 532a of the taper ring 530, which is a ring body. Includes surface 532b. In other words, the third inner peripheral surface 517 also serves as the inclined surface 532b.

That is, in the following description, the inclined surface 532a of the tapered ring 530, which is a ring body, functions as a first inclined surface. On the other hand, the inclined surface 532b of the cylindrical portion 510A functions as a second inclined surface.

A more detailed description will be given with reference to the drawings.

As shown in FIG. 14, boss fixing nut 510 includes a flange portion 510B and a cylindrical portion 510A. A first thread groove 18 is formed in the first inner peripheral surface 16 of the flange portion 510B facing the boss body 120 . Cylindrical portion 510A has first outer peripheral surface 12 on the side opposite to the side where boss body 120 is located. A first thread 14 is formed on the first outer peripheral surface 12 .

A second screw thread 122 is formed at an end portion 120b of the boss body 120 located on the opposite side of the protrusion formed on the boss body 120 in the direction of the axis J. As shown in FIG. The second thread 122 is threaded with the first thread groove 18 formed in the boss fixing nut 510 .

The lock nut 20 fixes the boss fixing nut 510 to the boss body 120 . A part of the second inner peripheral surface 26 of the lock nut 20 is formed with a second thread groove 22 that engages with the first thread 14 formed on the boss fixing nut 510 . The lock nut 20 has a small hole portion 24 in at least a part of the remaining portion of the second inner peripheral surface 26 of the lock nut 20 to fit the rotating shaft 110 .

Here, the cylindrical portion 510A of the boss fixing nut 510 is formed such that a gap portion 510C is formed between the rotating shaft 110 and the cylindrical portion 510A. A tapered ring 530 is inserted into the gap 510C. The tapered ring 530 has an inclined surface 532a that faces and contacts an inclined surface 532b of the cylindrical portion 510A. When the lock nut 20 is screwed in the direction D2 of the boss fixing nut 510, the tapered surface 532a of the tapered ring 530 slips into the inclined surface 532b of the cylindrical portion 510A. In other words, the inclined surface 532b of the cylindrical portion 510A slides outside the inclined surface 532a of the tapered ring 530 of the cylindrical portion 510A. As a result, the cylindrical portion 510A moves away from the axis C of the rotating shaft 110 in the direction intersecting with the axis C, so that the outer diameter of the cylindrical portion 510A increases. Therefore, as shown in FIG. 14, the cylindrical portion 510A, whose outer diameter is enlarged by the tapering 530, has a direction intersecting the axis C and an outer diameter with respect to the boss fixing nut 510 and the lock nut 20. A force F1 is produced which is a directed action. Therefore, the boss body 120 generates a force F2 as its reaction. As a result, in the direction crossing the axis C, the boss body 120 is strongly pressed toward the axis C in all directions from around the boss fixing nut 510 and the lock nut 20 . In other words, the axis J (rotation center) of the boss fixing nut 510 , the lock nut 20 and the taper ring 530 all coincide with the axis C (rotation center) of the boss body 120 . Therefore, it is possible to suppress core runout of the boss body 120, which is a body of rotation, and by extension, the rotor plate 130. As shown in FIG.

It is preferable that the contact surface (sliding surface) where the inclined surface 532a of the tapered ring 530 and the inclined surface 532b of the cylindrical portion 510A contact each other has a large coefficient of friction.

With the following configuration, it is possible to obtain even more remarkable effects.

As shown in FIG. 15, a tapered ring 530, which is a ring body, may have a slit 536 formed so that its extension line intersects the axis C. As shown in FIG. In other words, tapered ring 530 , which is a ring body, has slit 536 . Here, the extension line of the slit 536 refers to a line extending in the direction in which the slit 536, which is a narrow gap, is cut.

Alternatively, as shown in FIGS. 16 and 17, the tapered ring 530, which is a ring body, may have a plurality of slits 536 formed so that the extension line thereof intersects the axis C. As shown in FIGS. In other words, tapered ring 530 has a plurality of slits 536 . Extension lines of the plurality of slits 536 intersect the axis C, respectively. On a plane perpendicular to the axis C, the plurality of slits 536 may be positioned at intervals in the circumferential direction centered on the axis C, respectively.

The slit 536 may be formed along the inclined surface 532a. When the center line of the slit 536 is extended, the extension line should intersect the axis C.

In other words, on a plane orthogonal to the axis C, the plurality of slits 536 may be positioned radially around the axis C and circumferentially at appropriate angles.

As a particularly preferable example, as shown in FIG. 16, each slit 536 may be positioned at every θ1=120°. Alternatively, as shown in FIG. 17, each slit 536 may be positioned at every θ2=90°.

In the specific example shown in FIGS. 16 and 17, the slits 536 are equally spaced. Equal spacing or an appropriate angle means that the holding forces applied to the rotating shaft 110 by the respective inclined surfaces 532a divided by the respective slits 536 are equal, and does not mean mathematical equality. Typically, variations due to manufacturing tolerances are within the range of equidistant intervals or appropriate angles as referred to in this embodiment.

With this configuration, in the direction intersecting the axis C, the tapered ring 530 presses the boss body 120 more strongly in all directions from around the boss fixing nut 510 and the lock nut 20 toward the axis C. can be done. That is, the taper ring 530 can adjust the strength with which the boss body 120 is tightened within a range that can be adjusted by the width dimension of the slit 536 . Therefore, the accuracy with which the axis J (rotational center) of the boss fixing nut 510, the lock nut 20, and the tapered ring 530 coincide with the axis C (rotational center) of the boss body 120 is improved. Therefore, it is possible to further suppress core runout of the boss body 120, which is a body of rotation, and by extension, the rotor plate 130 as well.

Especially when three slits 536 shown in FIG. 16 or four slits 536 shown in FIG. The number of man-hours for forming the slits 536 in the inclined surface 532a can also be achieved within a moderate number of man-hours.

As shown in FIG. 18, the slit 536a should have a slit width W2 on the opening 536c side that is wider than the slit width W1 on the tip 536b side. In other words, the slit 536a of the tapered ring 530 has a slit width W2 on the opening 536c side of the tapered ring 530 that is wider than the slit width W1 on the tip 536b side of the tapered ring 530 .

With this configuration, even if a gap is generated between the inner peripheral surface of the tapered ring 530 and the outer peripheral surface of the rotating shaft 110 due to some factor, the difference between the slit width W2 and the slit width W1 is enough to fill the gap. Absorb. That is, due to the presence of the difference between the slit width W2 and the slit width W1, the taper ring 530 and the rotating shaft 110 can always secure an appropriate holding force.

As is clear from the above description, in the third embodiment described above, the boss fixing nut 510 has a shape that combines the boss fixing nut 10 described in the first embodiment and the outer ring 30a. Therefore, in this configuration, the tapered ring 530 has an effect corresponding to that of the inner ring 30b described in the first embodiment. In other words, in the third embodiment, the taper ring 530 can be composed of one member compared to the first embodiment. Therefore, in the third embodiment, as compared with the mounting mechanism 40 shown in the first embodiment, the assembling workability is improved.

As described above, the third inner peripheral surface 517 of the first nut 510 used in the mounting mechanism 540 of the present embodiment is formed on the inclined surface 532b facing the first inclined surface corresponding to the inclined surface 532a. It includes a corresponding second inclined plane.

As a result, workability in assembling the mounting mechanism 540 is improved.

Moreover, the tapered ring 530, which is a ring body, may have a slit 536 in the direction along the axis C.

Moreover, the tapered ring 530, which is a ring body, may have a plurality of slits 536 formed in a direction along the axis C. As shown in FIG. On a plane orthogonal to the axis C, the plurality of slits 536 may be positioned at regular intervals along the circumference of the axis C. As shown in FIG.

In addition, the slit 536a of the tapered ring 530, which is a ring body, has a slit width W2 on the side of the opening 536c of the tapered ring 530, which is a ring body, which is wider than the slit width W1 on the side of the tip 536b of the tapered ring 530, which is a ring body. Just do it.

(Embodiment 4)
A configuration of the mounting mechanism 640 according to the fourth embodiment will be described.

FIG. 19 is a schematic cross-sectional view showing the action of attachment mechanism 640 on rotating shaft 110 according to the fourth embodiment of the present disclosure. FIG. 20 is a perspective view of one member that configures the mounting mechanism 640 according to Embodiment 4 of the present disclosure. FIG. 21 is a front view of one member that configures attachment mechanism 640 according to Embodiment 4 of the present disclosure. FIG. 22 is a front view of another member that configures attachment mechanism 640 according to Embodiment 4 of the present disclosure. FIG. 23 is a perspective view of another member that configures attachment mechanism 640 according to Embodiment 4 of the present disclosure.

In describing the mounting mechanism 640, the same reference numerals are assigned to the same components as the components 1 to 3 described above, and the description is incorporated.

As shown in FIG. 19 , lock nut 620 , which is a second nut used in mounting mechanism 640 , has convex portion 622 reaching between second inner peripheral surface 626 and rotating shaft 110 . The convex portion 622 includes an inclined surface 632a facing an inclined surface 632b of the tapered ring 630, which is a ring body.

That is, in the following description, the inclined surface 632b of the tapered ring 630, which is a ring body, functions as a first inclined surface. On the other hand, the inclined surface 632a of the convex portion 622 functions as a second inclined surface.

A more detailed description will be given with reference to the drawings.

As shown in FIG. 19, the boss fixing nut 10 includes a flange portion 10B and a cylindrical portion 10A. A first thread groove 18 is formed in the first inner peripheral surface 16 of the flange portion 10B facing the boss body 120 . The cylindrical portion 10A has a first outer peripheral surface 12 on the side opposite to the side where the boss body 120 is located. A first thread 14 is formed on the first outer peripheral surface 12 .

A second screw thread 122 is formed at an end portion 120b of the boss body 120 located on the opposite side of the protrusion formed on the boss body 120 in the direction of the axis J. As shown in FIG. The second thread 122 is screwed into the first thread groove 18 formed in the boss fixing nut 10 .

The lock nut 620 secures the boss fixing nut 10 to the boss body 120 . A part of the second inner peripheral surface 626 of the lock nut 620 is formed with a second thread groove 22 that engages with the first thread 14 formed on the boss fixing nut 10 . The lock nut 620 has a small hole 24 in at least part of the remainder of the second inner peripheral surface 626 of the lock nut 620 to fit the rotating shaft 110 .

Here, the cylindrical portion 10A of the boss fixing nut 10 is formed such that a gap portion 610C is formed between the rotating shaft 110 and the cylindrical portion 10A. A tapered ring 630 is inserted into the gap 610C. The tapered ring 630 has an inclined surface 632b that faces and contacts an inclined surface 632a of the projection 622 . When the lock nut 620 is screwed in the direction D<b>2 of the boss fixing nut 10 , the taper ring 630 has an inclined surface 632 b that slips inside the inclined surface 632 a of the projection 622 . In other words, the slanted surface 632 a of the convex portion 622 slides outside the slanted surface 632 b of the tapered ring 630 . As a result, the projection 622 moves away from the axis C of the rotating shaft 110 in the direction intersecting with the axis C, so that the outer diameter of the projection 622 increases. Therefore, as shown in FIG. 19, the convex portion 622 whose outer diameter is enlarged by the tapering 630 acts on the boss fixing nut 10 in a direction intersecting the axis C and outward. A certain force F1 is generated. Therefore, the boss body 120 generates a force F2 as its reaction. As a result, in the direction crossing the axis C, the boss body 120 is strongly pressed toward the axis C in all directions from around the boss fixing nut 10 and the lock nut 620 . That is, the axis J (rotation center) of the boss fixing nut 10 , the lock nut 620 and the taper ring 630 all coincide with the axis C (rotation center) of the boss body 120 . Therefore, it is possible to suppress core runout of the boss body 120, which is a body of rotation, and by extension, the rotor plate 130. As shown in FIG.

It is preferable that the contact surface (sliding surface) where the inclined surface 632b of the tapered ring 630 and the inclined surface 632a of the convex portion 622 contact each other has a large coefficient of friction.

With the following configuration, it is possible to obtain even more remarkable effects.

As shown in FIG. 20, a tapered ring 630, which is a ring body, may have a slit 636 formed so that its extension line intersects the axis C. As shown in FIG. In other words, tapered ring 630 , which is a ring body, has slit 636 . Here, the extension line of the slit 636 refers to a line extending in the direction in which the slit 636, which is a narrow gap, is cut.

Alternatively, as shown in FIGS. 21 and 22, a tapered ring 630, which is a ring body, may have a plurality of slits 636 formed so that the extension line intersects the axis C. As shown in FIG. In other words, tapered ring 630 has a plurality of slits 636 . Extension lines of the plurality of slits 636 intersect the axis C, respectively. On a plane perpendicular to the axis C, the plurality of slits 636 may be positioned at intervals in the circumferential direction centered on the axis C, respectively.

The slit 636 may be formed along the inclined surface 632b. When the center line of the slit 636 is extended, the extended line should intersect the axis C.

In other words, on a plane perpendicular to the axis C, the plurality of slits 636 may be positioned radially around the axis C and circumferentially at appropriate angles.

As a particularly preferable example, as shown in FIG. 21, each slit 636 may be positioned at every θ1=120°. Alternatively, as shown in FIG. 22, each slit 636 may be positioned every θ2=90°.

In the specific example shown in FIGS. 21 and 22, the slits 636 are evenly spaced. Equal spacing or an appropriate angle means that the holding forces applied to the rotating shaft 110 by the respective inclined surfaces 632b divided by the respective slits 636 are equal, and does not mean mathematical equality. Typically, variations due to manufacturing tolerances are within the range of equidistant intervals or appropriate angles as referred to in this embodiment.

With this configuration, in the direction intersecting the axis C, the tapered ring 630 presses the boss body 120 more strongly in all directions from around the boss fixing nut 10 and the lock nut 620 toward the axis C. can be done. That is, the taper ring 630 can adjust the strength with which the boss body 120 is tightened within a range that can be adjusted by the width dimension of the slit 636 . Therefore, the accuracy with which the axis J (rotational center) of the boss fixing nut 10, the lock nut 620, and the tapered ring 630 all coincide with the axis C (rotational center) of the boss body 120 is improved. Therefore, it is possible to further suppress core runout of the boss body 120, which is a body of rotation, and by extension, the rotor plate 130 as well.

Especially when three slits 636 shown in FIG. 21 or four slits 636 shown in FIG. The number of man-hours for forming the slits 636 in the inclined surface 632b can also be achieved within a moderate number of man-hours.

As shown in FIG. 23, the slit 636a should have a slit width W2 on the opening 636c side that is wider than the slit width W1 on the tip 636b side. In other words, the slit 636a of the tapered ring 630 has a slit width W2 on the opening 636c side of the tapered ring 630 that is wider than the slit width W1 on the tip 636b side of the tapered ring 630 .

With this configuration, even if a gap is generated between the inner peripheral surface of the tapered ring 630 and the outer peripheral surface of the rotating shaft 110 due to some factor, the difference between the slit width W2 and the slit width W1 is enough to fill the gap. Absorb. That is, due to the presence of the difference between the slit width W2 and the slit width W1, the taper ring 630 and the rotating shaft 110 can always secure an appropriate holding force.

As is clear from the above description, in the fourth embodiment described above, the lock nut 620 has a shape combining the lock nut 20 described in the first embodiment and the outer ring 30a. Therefore, in this configuration, the tapered ring 630 has a function corresponding to that of the inner ring 30b described in the first embodiment. That is, in the fourth embodiment, the taper ring 630 can be constructed with one member as compared with the first embodiment. Therefore, in the fourth embodiment, as compared with the mounting mechanism 40 shown in the first embodiment, workability of assembly is improved.

As described above, second nut 620 used in mounting mechanism 640 of the present embodiment has convex portion 622 reaching between second inner peripheral surface 626 and rotating shaft 110 . The convex portion 622 includes a first inclined surface corresponding to the inclined surface 632b and a second inclined surface corresponding to the inclined surface 632a opposite to the inclined surface 632b.

As a result, the core run-out of the rotating body corresponding to the boss body 120 can be suppressed.

Also, the tapered ring 630, which is a ring body, may have a slit 636 in the direction along the axis C. As shown in FIG.

Also, the tapered ring 630, which is a ring body, may have a plurality of slits 636 formed in the direction along the axis C. As shown in FIG. On a plane orthogonal to the axis C, the plurality of slits 636 may be positioned at regular intervals along the circumference of the axis C. As shown in FIG.

In addition, the slit 636a of the tapered ring 630, which is a ring body, has a slit width W2 on the side of the opening 636c of the tapered ring 630, which is a ring body, that is wider than the slit width W1 on the side of the tip 636b of the tapered ring 630, which is a ring body. Just do it.

(Embodiment 5)
A configuration of an attachment mechanism according to Embodiment 5 will be described.

24 is a front view of one member that configures an attachment mechanism according to Embodiment 5 of the present disclosure. FIG. 25 is a front view of another member that configures the attachment mechanism according to Embodiment 5 of the present disclosure. FIG.

In describing the mounting mechanism, the same reference numerals are assigned to the same components as those of the first to fourth embodiments described above, and the description is incorporated.

As shown in FIG. 24, tapered ring 730, which is a ring body, has a plurality of slits 736 on inclined surface 732b. In the plurality of slits 736, adjacent openings 736c are positioned at equal intervals in the circumferential direction around the axis C when viewed from the axis C direction. Each of the plurality of slits 736 is formed with a notch in the direction of the axial center C and the twisted position. Therefore, adjacent tips 736b are positioned at regular intervals in the circumferential direction.

The shape of the notch forming the slit can be realized by a linear slit 736 as shown in FIG. Alternatively, the shape of the notch forming the slit can also be realized by a spiral slit 736a as shown in FIG.

Slits 736 and 736a of this shape can be formed in each inclined surface shown in the first to fourth embodiments described above.

Even if the slits 736 and 736a of this shape are used, the same effects as those of the first to fourth embodiments described above can be obtained.

(Modification of Embodiment)
As a modification of the embodiment according to the present disclosure, a known locking means such as a metal washer is provided between the facing surfaces of the flange portion 10B of the boss fixing nut 10 and the lock nut 20. may By doing so, it is possible to obtain long-term rotational stability in the boss body 120 including the rotating plate 130 .

An attachment mechanism according to the present disclosure can attach a rotating body to a rotatable shaft in an apparatus including the rotating body. A mounting mechanism according to the present disclosure is used, for example, for detecting rotational position in a servo system. The mounting mechanism according to the present disclosure is useful for an encoder or the like that detects the absolute position of a machine tool tool or the like with high accuracy and high resolution.

10, 510 Boss fixing nut (first nut)
10A, 510A cylindrical portion 10B, 510B flange portion 10C, 410C, 510C, 610C void portion 10d, 20a inner surface 12 first outer peripheral surface 14 first thread 16 first inner peripheral surface 17, 517 third inner peripheral surface Face 18 First thread groove 20, 620 Lock nut (second nut)
22 Second thread groove 24 Small hole 26, 626 Second inner peripheral surface 30, 430, 530, 630, 730 Tapering (ring body)
30a outer ring 30b inner ring 32, 32a, 32b, 432a, 432b, 532a, 532b, 632a, 632b, 732b inclined surface 34, 34a, 120c end surface 36, 36a, 436, 436a, 536, 536a, 636, 636a, 736 , 736a Slit 36b, 436b, 536b, 636b, 736b Tip 36c, 436c, 536c, 636c, 736c Opening 40, 440, 540, 640 Mounting mechanism 100 Encoder 100a Housing 110 Rotating shaft 120, 460 Boss body (rotating body)
120a protrusion 120b, 460b end 122 second thread 124 second outer peripheral surface 130 rotating plate (rotating body)
131 translucent window 140 bearing mechanism 151 LED element (light emitting element)
152 phototransistor (light receiving element)
200 electric motor 210 rotor 212 rotor core 214 magnet hole 216 permanent magnet 220 bearing 222 case 230 stator 232 stator core 234 winding 236 insulator 462 tapered portion 622 convex portion

Claims (16)

A mounting mechanism for mounting a rotating body on a rotating shaft,
a cylindrical portion penetrated by the rotating shaft, extending along the axis of the rotating shaft, and having a first outer peripheral surface including a first screw thread;
a flange portion that protrudes in a direction that intersects the axial center and is opposite to the side on which the rotating shaft is located, and that has a first inner peripheral surface including a first thread groove;
a first nut comprising
the rotating shaft passes through,
a second thread groove formed in a portion of the second inner peripheral surface facing the rotating shaft and screwed with the first thread;
a small hole formed in a portion of the second inner peripheral surface other than the second thread groove and fitted with the rotating shaft;
a second nut comprising
The rotating shaft passes through and is located between the third inner peripheral surface of the cylindrical portion and the rotating shaft, and the first nut and the second nut are screwed together in a direction toward each other. a first inclined surface that converts a force applied from each of the first nut and the second nut acting in a direction along the axis into a force acting in a direction intersecting the axis; a ring body having
an attachment mechanism. 2. The attachment mechanism according to claim 1, wherein said ring body is a pair of tapered rings further having a second inclined surface facing and abutting said first inclined surface. 3. The attachment mechanism according to claim 2, wherein, of said pair of tapered rings, the tapered ring located on the rotating shaft side has a slit, and an extension line of said slit intersects said axis. Of the pair of tapered rings, the tapered ring located on the rotating shaft side has a plurality of slits, and extension lines of the plurality of slits respectively intersect the axial center,
3. The attachment mechanism according to claim 2, wherein said plurality of slits are spaced apart in a circumferential direction about said axis on a plane orthogonal to said axis. 5. The mounting mechanism according to claim 3, wherein the slit of the tapered ring located on the rotating shaft side has a wider slit width on the opening side of the tapered ring than on the tip side of the tapered ring. . The rotating body has a tapered portion extending between the third inner peripheral surface and the rotating shaft in a direction along the axis,
2. The attachment mechanism according to claim 1, wherein said tapered portion includes a second inclined surface facing said first inclined surface. 7. The attachment mechanism according to claim 6, wherein said tapered portion has a slit, and an extension of said slit intersects said axis. the tapered portion has a plurality of slits, extension lines of each of the slits intersecting the axis,
7. The attachment mechanism according to claim 6, wherein said plurality of slits are spaced apart in a circumferential direction about said axis on a plane orthogonal to said axis. 9. The attachment mechanism according to claim 7, wherein said slit of said tapered portion has a slit width on an opening side of said tapered portion that is wider than a slit width on a distal end side of said tapered portion. 2. The mounting mechanism according to claim 1, wherein said third inner peripheral surface of said first nut includes a second inclined surface facing said first inclined surface. The second nut further has a convex portion reaching between the second inner peripheral surface and the rotating shaft, and the convex portion forms a second inclined surface facing the first inclined surface. 2. The attachment mechanism of claim 1, comprising: 12. The attachment mechanism according to claim 10, wherein said ring body has a slit extending along said axis. The ring body has a plurality of slits formed in a direction along the axis,
12. The attachment mechanism according to claim 10, wherein said plurality of slits are positioned at equal intervals in a circumferential direction around said axis on a plane perpendicular to said axis. 14. The attachment mechanism according to claim 12, wherein said slit of said ring body has a slit width on an opening side of said ring body wider than a slit width on a front end side of said ring body. The rotating body is
A boss extending along the axis of the rotating shaft through which the rotating shaft passes, and having a second outer peripheral surface including a second screw thread that is screwed with the first thread groove included in the flange portion. body and
a rotating plate mounted so as to intersect with the axis;
12. The attachment mechanism of any one of claims 1, 2, 6, 10 and 11, wherein the attachment mechanism is an encoder comprising: a rotor having a rotor core attached to the rotating shaft;
a bearing that rotatably supports the rotating shaft;
a stator facing the rotor;
with
An electric motor in which the encoder is attached to the rotary shaft using the attachment mechanism according to claim 15 .

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